Cosmic Rays Used to Peer Inside Pyramid: Photos

Located at the royal necropolis of Dahshur, about 25 miles south of Cairo, the Bent Pyramid, so named because of its sloping upper half, was built under the Old Kingdom Pharaoh Sneferu (about 2600 BC). It's the first with smooth faces after generations of stepped pyramids.
The monument has two entrances, one on the north side and one on the west side. These entries open on two corridors leading to two burial chambers arranged one above the other.
It was speculated that pharaoh Sneferu rests inside the pyramid in an undiscovered burial chamber, but innovative scanning technology ruled out the hypothesis as it did not detect any additional chamber of the size of the upper chamber or beyond.

Specialist Kunihiro Morishima, from the Institute for Advanced Research of Nagoya University, Japan, installed 40 muon detector plates inside the lower chamber of the Bent pyramid.
Covering a surface of about 10 square feet in the pyramid’s lower chamber, the plates contained two emulsion films that are sensitive to cosmic particles that continually shower the Earth’s surface.

Just like X-rays pass through our bodies allowing us to visualize our skeleton, these elementary particles, weighing around 200 times more than electrons, can very easily pass through any structure, even large and thick rocks, such as mountains.
The plate detectors allow researchers to discern void areas -- places where muons cross without problem -- from denser areas where some muons are absorbed or deflected.

Morishima’s team retrieved the detector plates from the Bent Pyramid in January 2016 after 40 days of exposure. This is the maximal lifetime of chemical emulsions within the temperature and humidity conditions inside that pyramid.

“From the detector plates, more than 10 million muon tracks were analyzed," Mehdi Tayoubi, co-director of the ScanPyramids missio, told Discovery News. "We count the muons and according to their angular distribution we are able to reconstruct an image."
“For the first time ever, the internal structure of a pyramid was revealed with muon particles," he added.